The striped mealybug Ferrisia virgata (Ckll.) (Hemiptera: Pseudococidae) attacks many host plants including shrubs and trees in Egypt. The aim of this work is to study the population densities of striped mealybug and the effect of biotic and abiotic factors on the insect population and the preferable direction for the insect stages on ornamental corn shrubs, Dracena fragrans in Al-Zohria gardens at Cairo during two successive years (2014-2015) (2015-2016). The results showed that the highest number of F. virgata insects occurred during Sep. in the first year, while it occurred during Nov. in the second year, with average (93.5 and 42.1 insect / sample) in the first and second years respectively. The general mean number of F. virgata has of 24.7 during the first year while it was 16.6 in the second year of investigation. The results showed that the insect population was highest in autumn with average (64.3 and 44.6 insect/ sample) in the first and second year respectively, whereas the lowest mean was in spring (2.7 and 1.5 insect / sample) during the two successive years. The data revealed insignificant relation between daily maximum, range and minimum of temperature and natural enemies on population activity. On the other hand the relation between the relative humidity and the population activities was highly significant positive correlation in both two years. In respect to preferable direction, results showed that the northeastern direction was the preferable direction for the population activity in the both years of the study.

Present work was conducted for studying biological control of the termite psammotermes hypostoma (sand termite) This study includes the following results: Toxicity results of Bacillus thuringiensis var. kurstaki against the termite psammotermes hypostoma revealed higher mortality values at the highest concentrations used 6gm/L, while the lowest concentrations gave moderate mortality values 53%. Use of Beauveria bassiana, indicated negligible mortality values ranged between from (3.6-16.2%) at the three tested concentration. Application of nematodes (Steinernema carpocapsae) against subterranean termites, mortality has begun 24 hours post-treatment. The first concentration represented (40.2%) mortality, the second concentration represented (78.2%), and the highest used concentration gave complete mortality values (100%). The LT 50 for Dipel 2X was 2.6, 3.01 and 4.9 days and 2.2, 3.2 and 7.3 days for Bacillus thuringiensis approximately.

The present work studied the main biotic factors affecting the population of S. lividipes. The different stages of the insect life cycle are described and investigated. The insect showed one generation per year under the Egyptian condition. The mean number of eggs per female during the oviposition period (29–45 days) was 222.1 ± 57.0. The preoviposition, incubation, larval and pupal periods of the insect were 7.5 months, 7–8, 29–30 and 9–12 days respectively. Five larval instars for the insect are recorded. The duration of each of them is given. Zusammenfassung Über die Entwicklung und Lebensweise des Blattrandkäfers, Sitona lividipes Fhs. (Col., Curculionidae) Der Blattrandrüsselkäfer, S. lividipes, hat in Ägypten nur 1 Generation im Jahr. Die Durchschnittszahl der Eier pro Weibchen betrug 222,1 ± 57,0, die Voreiablagezeit 7,5 Monate. Die Eiablagezeit schwankte im Durchschnitt zwischen 29 und 45 Tagen. Die Inkubationsperiode dauerte 7 bis 8 Tage. Die Larvenzeitdauer betrug 29 bis 30 und die Verpuppungsdauer 9 bis 12 Tage. Es gab 5 Larvenstadien. Die Adulten von S. lividipes lebten etwa 1 Jahr.

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Study of sand termite, P. hypostoma (Desn.), throughout two successive years in 1995 and 1996, clarified that, the termite individuals were abundant during winter and autumn seasons. The workers, first and second nymphs and soldiers were abundant in the winter and reduced during summer season. On the other hand, swarming of winged castes (alates) was occurred during autumn and summer months. The population of workers represented the highest percentages from the total numbers of gallery, followed by soldiers, nymphs and alates. In summer 1995 and 1996, the attraction rate of traps in the tested area (surface activity) was higher during autumn and winter and lower in summer, while the surface activity (food consumption and soil translocated without insects) was higher during summer and autumn, while was lower during winter season throughout 1995 and 1996. Also the highest number of caughted traps was recorded during winter and the lowest one occurred during summer. Food consumption by termites was higher during spring and summer, while it was lower during winter. Soil translocation (construction) showed also the same trend.